The Mystery of the Mantis Shrimp: Surviving the Impact of a .22 Caliber Bullet (2014)

Undergraduate: Maryam Kazemzadeh-Atoufi

Faculty Advisor: Doreen Theirauf
Department: Physics & Astronomy

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The peacock mantis shrimp uses dactyl clubs (i.e. fingers) to punch its victims with 1500N of force, often dismembering them. Upon impact, water is forced away so quickly that cavitation bubbles are formed and immediately collapse, creating a second shockwave that generates heat and light. The mystery of the mantis shrimp lies not only in the ability of the animal to store enough energy to deliver the punch and optimize the transfer from elastic to kinetic energy, but also in its ability to resist the impact of and survive its own strike. Thus, the primary site of elastic energy storage is located in highly mineralized internal structures of the raptorial appendage called ventral bars. These bars behave as Hookean springs and amplify power output. To resist damage, the telson, abdominal plate struck in ritualized fighting, behaves as an energy absorbing mechanism with a densely mineralized center surrounded by an area of lower mineralization. This pattern reflects an inelastic structure that allows for the telson to dissipate 69% of impact energy. The mantis shrimp is one of the most powerful and damage-resistant animals. By studying the attack mechanism and the mineralization patterns and structures that allow the shrimp to survive the impact and shockwave, researchers can apply these structures to modern architecture and the development of body armor using the properties of the mantis shrimp¿s limbs.